General Chemistry Ch. 4 – Compounds and Stoichiometry

molecule
two or more atoms held together by covalent bonds
molecular weight and formula weight

  • molecular weight is the sum of the atomic weights of all the atoms in a molecule in atomic mass units (amu)
  • formula weight is found by adding up the atomic weights of the constituent ions according to its empirical formula, also in amu per molecule

mole
a quantity of any substance equal to the number of particles defined as Avogadro’s number (6.022 x 1023 mol-1)
molar mass
the mass of one mole of a compound expressed in grams per mole
gram equivalent weight
the amount of a compound that produces one equivalent of the particle of interest; calculated by dividing molar mass by the number of particles of interest produced or consumed per molecule of the compound in the reaction
normality
measure of concentration expressed in equivalents/L
law of constant composition
any pure sample of a given compound will contain the same elements in an identical mass ratio
empirical formula
the simplest whole-number ratio of the elements in the compound
molecular formula
the exact number of atoms of each element in the compound and is a multiple of the empirical formula
percent composition determination
divide the mass of the element in the formula by its molar mass and multiply by 100
combination reaction
two or more reactants forming one product
decomposition reaction
a single reactant breaks down into two or more products, usually as a result of heating, high-frequency radiation or electrolysis
combustion reactions
occur when a fuel and an oxidant (typically oxygen) react and fro products of water and carbon dioxide (if the fuel is a hydrocarbon)
single-displacement reactions
occur when an ion of one compound is replaced with another element
double-displacement reactions
occur when elements from two different compounds trade places with each other to form two new compounds
neutralization reactions
special kind of double-displacement reaction in which an acid reacts with a base to produce a salt (and, usually, water)
What are the naming conventions for elements that can form more than on positive ion?

  • the charge is indicated by a Roman numeral in parentheses following the name of the element ie Iron(II)
  • less common, add -ous or -ic to the root to represent the ions with lesser and greater charger, respectively

What is the naming convention for elements that form oxyanions?

-ite for less oxygen; -ate for more

Hypo- as a prefix for less if more than 2 oxyanions and per- as a prefix for more

Borate
BO33-

Chromate

Dichromate

CrO42-

Cr2O72-

Thiocyanate
SCN
Ammonium
NH4+
acetate
C2H3O2
Tagged In :

Get help with your homework


image
Haven't found the Essay You Want? Get your custom essay sample For Only $13.90/page

Sarah from studyhippoHi there, would you like to get such a paper? How about receiving a customized one?

Check it out